/**
 * https://leetcode.cn/problems/longest-palindromic-subsequence/submissions/
 * 516.最长回文子序列
 * medium 陈贝纯 11.18
 * 区间dp
 */

class Solution {
public:
    int longestPalindromeSubseq(string s) {
        int n=s.size();
        vector<vector<int>> dp(n,vector<int>(n));
        for(int i=n-1;i>=0;--i){
            dp[i][i]=1;
            for(int j=i+1;j<n;++j){
                if(s[i]==s[j])
                dp[i][j]=dp[i+1][j-1]+2;
                else
                dp[i][j]=max(dp[i][j-1],dp[i+1][j]);
            }
        }
        return dp[0][n-1];
    }
};